Coconut Oil
For cooking, sautéing, baking, and more, coconut oil should be in every vegan chef's pantry. It melts easily, so you can use it for greasing a pan or even just as a 1:1 substitute for butter in baked goods. If you're feeling really brave, try coconut oil on your morning toast.
Vegetable Oil
You can use it as a substitute for melted or softened butter in recipes, but if the recipe calls for you to "cut in" the butter or just a regular stick of butter, vegetable oil is probably not your best option.
Plant-based Butter Alternatives
For all of your other plant-based butter needs, there are plenty of completely vegan alternatives to butter on the shelves of your local grocery store.